


For Science

by epochryphal



Category: Kill la Kill
Genre: Anal, Consensual Kink, Established Relationship, Gender-Neutral Pronouns, Genderqueer Character, Happy Ending, Kink Negotiation, M/M, No Explicit Genitals, Nonbinary Character, Other, POV Second Person, Risk Aware Consensual Kink, Safeword Use, Safewords, Tentacles
Language: English
Status: Completed
Published: 2014-10-02
Updated: 2014-10-02
Packaged: 2018-02-19 14:52:24
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,889
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/2392358
Author URL: https://archiveofourown.org/users/epochryphal/pseuds/epochryphal
Summary: <blockquote class="userstuff">
              <p>You transform, secure everything, cross your arms against your chest and keep them there. Tailor Regalia is your only arms now.</p><p>With a breath, you glide into the room.</p><p>---</p><p>Houka's secret fantasy is to get royally fucked by Shiro's Tailor Regalia. Thing is, even though ey's already in a relationship with Shiro, they only do kink—not sex. But when Jakuzure spills the beans, Iori confronts Inumuta about hiding such a thing, and negotiation ensues.</p>
            </blockquote>





	For Science

**Author's Note:**

> Minor **dissociation trigger warning** , with a happy ending.
> 
> Houka uses Spivak/Elverson pronouns because ey's a huge non-binary nerd. (Shiro is agender and uses singular they, though it doesn't come up in-fic.)
> 
> And ハ is the sound effect "ha" like breathing. It'll come up later.

"Please." Houka's voice cracks, sending tiny fissures through your heart. "As if I'd—be so insensitive, to ask for such a thing."

Your frown deepens, and you cross your arms and study your partner. Ey is looking away, collar and hackles raised; eir glasses are angled to catch the light just right for a glare that obscures eir eyes. Quite a talent of eirs, but you can read far more from the lines of eir posture: unnaturally still, stiffened in a faux-relaxed pose, the slight folds of eir uniform even less visible than usual since ey isn't slouching in the least. Everything about em screams tension.

You let out an exasperated sigh and reach up, grab your enbyfriend's collar and yank eir down to face you. "Houka." Ey finally meets your eyes, and the wariness there isn't surprising, but it still stings a bit. You tsk audibly. "What did we say about asking?"

Ey glances at your fingers, and you shift your grip just enough to allow the life fibers to part, revealing eir hesitant mouth. "To—do that," ey replies cautiously.

You block the collar from reclosing with your hand and nod once, trying to appear patient and not too stern, a look you've never mastered. "So. Can you grasp why I'm frustrated? That I had to stumble across my lover's secret fantasies through Jakuzure's wisecracks, instead of being told to my face?"

Houka makes a small noise at the word "lover" and stares at you, green eyes intense through eir azure glasses. You wait, calmly meeting eir gaze. Eir mouth tightens. "It has been my understanding that our relationship is. Despite our kink practices, and whatever Jakuzure might think of them, strictly." You watch eir throat as ey swallows. "Non-sexual, in nature."

You feel your expression soften, however marginally, at eir retreat into formality. "Ah." Releasing your grip on eir clothes, you massage the bridge of your nose, carefully considering your next words. "You remember our discussions of what a muddy line that is, of course. Still." You tilt your head to the left, considering em over your fingers. "I suppose you were trying to spare me."

"I would never risk us for a fantasy." Houka's voice is hoarse, and all the more piercing for it. "Never. And," ey adds fervently, glasses flashing, " _fuck_ Jakuzure for meddling in this shit."

"I thought," you say slowly, taking care to enunciate. "The idea was, for _you_ to get fucked—by this?" You pinch the collar of your dormant goku uniform between forefinger and thumb, raising your eyebrows.

Ey straightens up to full height so fast you suspect it's to conceal a shiver down eir spine. "Don't fuck with me about this, Iori." Eir voice is lower than you've heard it in a long time, possibly ever. "Not this."

"I'm not." Your reply is simple and, you think, disarming. Houka looks off-balance, likely caught between a dozen flawed analyses. You step forward and wrap your arms around em, hugging your bodies snug together, your left ear to eir heartbeat. It's about as fast as you expected. "I wouldn't." You tighten your embrace, willing less distance between you. "When did we fall so out of synch, for you to think that?"

Slowly, your partner puts eir arms around you, and tucks your head under eir chin. You both stand there for awhile, just breathing.

Eventually, Houka cups the back of your head in one hand, signaling you to look up at em. The question in eir eyes is obvious, and you answer.

"No promises. But let's at least discuss it. Give me a chance to say yes, will you?"

\---

The preparations take some time.

First, you need an idea of what, exactly, Houka's fantasies consist of. With the aid of some hentai vids as proxy, you slowly coax em to point out which components are hot and which incidental, distracting, or turnoffs. It's all quite…fascinating. That's what you tell em, too: that it will be an intriguing experiment. Rather like your approach when topping em in general, your interest lies in seeing what your hands can do. Ey seems to accept that line of reasoning.

Once you feel you have an adequate vision of concept, you turn your attention to the details: namely, safety. Your usual color-scheme of safewords applies, plus non-verbal signals including double-taps and marble-drops. "Safeword" itself is of course a failsafe, and your partner stresses that you personally could tap out at any time, even now, whether due to too much pressure to perform, dissociation, dysphoria, disinterest or anything else great or small. Aftercare plans are arranged, supplies restocked, trigger contingencies rehashed. It's emotionally exhausting, and you both spend more time than usual crashed on the sofa, leaning together in casual intimacy and trying to relax.

And then there is the not-inconsiderable problem of equipment. Houka is initially against any alterations of Tailor Regalia's form, but you refuse to give ground on that front; you might be able to stitch your enbyfriend back together, but by the gods you would do anything to prevent that. You work out a compromise: preserve the artistic integrity of the scene while minimizing risk of unacceptable bodily harm. Ey sulks only a bit before sighing about common sense and your pragmatism.

Your personal free time becomes consumed by practice, perfecting your finesse with the arms, testing their reach and weight and all the other variables that had mattered little for tailoring itself. Synchronizing so intensely with the life fibers has added bonuses for your research, but while you permit yourself to take copious notes, you don't allow it to distract you from your purpose. Your laser-focus serves you well in this respect.

Throughout this planning phase, Houka has been excessively deferential, insisting on having you bottom for the sensation play you so love, declining your offers to switch. You both know it's about guilt, but ey pays such careful attention to all your favorite spots and buttons—and when you confront em about how unnecessary this all is, ey replies so sincerely that you "deserve it for being such a loving partner. Whether or not this whole idea goes anywhere." With that last bit of pressure lifted, you relent, and allow yourself to enjoy the extra attention. It makes the final adjustments, and the anticipation of Houka's reaction, all the sweeter.

Now, at long last, you finally feel ready.

\---

You transform, secure everything, cross your arms against your chest and keep them there. Tailor Regalia is your only arms now.

With a breath, you glide into the room.

Houka is facing away from the door, fiddling with an azure marble, pretending to be entranced and not know you're coming. The rapid rise and fall of eir chest is visible even from here, belying eir casual façade. Silently, you walk closer, appraising eir outfit: a tall black turtleneck that's started to fade, matching skinny jeans with holes in the knee, ratty slip-ons. Good. You'll feel no remorse shredding such trash.

You come to a stop a few feet away, and wait.

After a minute, Houka abruptly stops playing with the marble, clenches it in eir right fist, and pivots to face you.

Eir skin is both flushed and pale, color warring in the part of eir cheeks visible above eir collar. Trembling ever so slightly, ey looks you up and down and up again, pupils dilated behind eir glasses.

Ey hasn't seen you in Tailor Regalia since before that first discussion. You strike an imposing figure, you know; the spiraling sweep of fabric veiling your feet, the gasmask obscuring all but your eyes and tinting them the same green as Houka's. The collar swooping out like mandibles, granting you both extra height and extra alienness. Head held high, you wait.

"Shir—"

Your arms slam into Houka all at once, knocking em off balance before instantly hoisting em up into the air, twining around limbs and chest and neck.

Ey shouts in genuine surprise, flailing instinctively, and you frown and redouble your focus. Mindful of your spikes, you tighten the tentacle around eir throat, choking em silent. Feet kick wildly and hands scrabble at neck, until two more tentacles finish winding down eir arms and jerk them out away from eir body, molding em into a lovely t-shape. You loosen the throat arm, watching your prisoner gasp for oxygen, mouth already half-uncovered from the struggle. My, but ey is even more responsive than you anticipated.

You slow down, absently weaving a tentacle up Houka's torso, the head-sized sewing machine at the end nuzzling against eir chin and tipping it back. That earns you a quiet whine; very nice, if difficult to hear from this distance. Your spine tingles a little as you gradually bend eir arms down to eir sides, looping tentacles around waist and pinning wrists just below hips. Eir back arches, each breath more vocal now; your own breathing is faster, too.

Leisurely, you rotate your prey in the air, examining em from multiple angles, as though you were still deciding what to do with this curious creature you've caught. You turn em face-down parallel to the ground, tied into a straight line, and bring em down to your height, face within two inches of your visor. Keeping your expression impassive, you tilt eir chin this way and then that; eir mouth stays open, panting, tongue forward, collar askew and already wet with drool. Eir eyebrows form a perfect ハ shape, you think, appropriate to eir heavy breathing. Your eyes meet over eir glasses, and the longing you see there makes your heart ache.

When ey swallows, seeming about to speak, you move.

A few strides forward carry you across the room, bearing Houka before you to slam up against the wall and pin there, suspended above the ground. The whoosh of air as you knock the breath from eir lungs is…gratifying. Your fingers tighten their grip on your sleeves as you watch the stunned being recover; ey twitches feebly and looks beautifully disoriented.

You retract two of your tentacles partway, shifting them to extract Houka's arms from eir sides and lift them over eir head. Halfway up, ey starts struggling and writhing in place and, wouldn't you know it, manages to jerk a spike into eir forehead. Ey yelps and twists away; you clamp down on the instinct to instantly react, forcing yourself to finish stretching em out, wrists crossed high above eir head. You anchor them there, burying the snug mouth of a sewing machine into the wall around them. Houka's right hand is a tight fist around eir marble.

That secured, you turn your attention to inspecting the wound. Barely a scratch, it looks no deeper than anything from one of your previous injury scenes. A small bead of blood is welling up, slowly preparing to trickle down over eyebrow and into eye.

It's perfect.

You'd hoped the spikes would integrate themselves subtly into the scene somehow; they were on the list of possible safety compromises, and though all your practice—and nearby stash of first aid supplies—had left you confident enough to not modify them, it was a risk you were still hyper-conscious of. One you hoped to contend with only a bit longer.

Houka is staring at you, looking much too alert for your tastes. Lips still parted and partially visible, definitely breathing fast, but much too aware. Your mouth twists under your gasmask as a wave of frustration about that ridiculous faded collar obstructing your view washes over you. Time for phase two.

You unwind the free tentacle from eir pinned arms and, with the mouth of its sewing machine, bite into the hem of that hideous turtleneck and start ripping.

Your subject lets out a startled noise, watching as you efficiently tear along the seams and expose eir bare skin. Ey shivers at the touch of cool metal; you tighten your grip on eir torso to keep em still, and are rewarded by the close of eir eyes. Carefully, you sink your needles into that damned collar and, in one fluid motion, tear it off, sending the shredded shirt fluttering to the ground.

The jeans offer no more resistance, parting before your machines like cheap cotton. They fall to the floor with the slip-ons. You trace your cold up Houka's inner thighs, teasing them apart and winning a series of sharp inhales. Tenderly, you nip at the edge of eir boxer briefs, allowing needles to brush skin, eliciting the day's first moan. You pull, infinitely slowly, and the fabric stretches then gives way.

You leave the glasses. You want em to see.

Eir gaze burns as your tentacles glide back down eir shivering legs, spreading calves wide and fastening ankles to the wall, inches above the floor, with your mouths. Your last free arm curls lazily around eir abdomen and chest; ey arches naked against the wall, limbs pinned and helpless, breathing hard, blinking blood out of eir right eye.

Mm. You think you see the allure of pin-ups, now.

You incline your chin and the three anchored sewing machines detach from their arms, leaving the heavy metal embedded into the wall, trapping your prisoner's limbs in place. Eir breath hitches as the now-free arms slither back and hover beside your head, poised to strike again. At their ends are little power outlets, the in-built prongs retracting to form a smooth surface, rendering them for all the world genuine tentacles now. Strange to think a month ago, you had no idea you could do that.

Houka's eyes are huge and shimmering.

"Sh—Shiro—"

You constrict the tentacle still around eir ribcage, wrenching forth a pained gasp that makes your heart sing. Your last sewing machine head nuzzles at eir jawline, needles hissing dangerously as they sew the air. Eir whine is heavenly.

Catching eir eyes with yours to ensure ey is watching, you dip your free tentacles into the folds of fabric just beneath your groin. You read uncertainty battling desire in Houka's face; after a beat, your arms reemerge, producing a long, translucent bottle with what is clearly lubricant inside. Houka flushes deep, a lovely full-body suffusion of color as ey bites eir lower lip and desperately searches your visor for a sign of reassurance. Your brow softens as you allow yourself a small smile behind the mask, radiating encouragement and confidence, and you see the concern fade from your partner's eyes.

Gripping the bottle with your tentacles, you deftly pop the lid off, a move requiring hours of practice made well worth it by the astonished stare it elicits. Setting the container gently on the ground, you slowly sink your first tentacle into the goop; it displaces the liquid, causing it to ooze over the rim and down the sides to the ground. The appendage wriggles idly, brushing the bottle's insides, before pulling out with a sucking sound, coated in your special mixture of monster slime. You watch a thin line of drool dribble down your captive's chin as you submerge the other two; eir head has tilted slightly to the side, resting against a bound arm, and eir eyes have gone half-lidded. More, eir tongue rests atop eir bottom lip, in that silently begging expression you know so well.

You stretch out a tentacle toward eir mouth and let it hang in the air just out of reach. Ey strains toward it, keening; you tip eir head back with the machine at eir throat, your other two tentacles questing towards cheek and temple. They caress soft skin, laving it with shiny streaks of lubricant. You dab little dots around eir nose, letting em smell you: metallic, bitter, with a hint of sour. Ey groans.

"P—please." Houka's voice cracks, sending ripples down your spine. Outwardly impassive, you trail your tips down jawline, neck, collarbone, tracing patterns on eir chest. You nudge your still-hovering tentacle closer, teasing at eir yearning mouth and dripping onto eir bottom lip. Ey licks up a drop and shudders, swallowing and panting audibly, and you take pity.

Your tentacle probes at eir mouth and outstretched tongue, leaving smears of lube around parted lips before finally slipping inside. It fits perfectly, and as it fills eir mouth Houka moans low and long around it, lips rounded and plumping already. Eir eyelids close, fluttering as you slowly press deeper and recede, deep and recede, forward an inch and back half. Eir chest rises and falls faster, as ey pants around you sliding further along eir palate. Abruptly eir entire body heaves as you hit what must be eir gag reflex; you swiftly withdraw just a few centimeters, enough for em to subside into smaller tremors and longer moans.

You resume moving, undulating back and forth and up and down, barely tickling the edge of that gag spot with each pass. Already Houka's eyes are watering, more with each thrust; as you watch, a single tear trickles down eir cheek, mingling with the saliva and lube leaking from eir mouth. You coil inside, stretching eir mouth full, before drawing all the way back out, savoring the sucking sound and trail of spit; ey whines in complaint, lapping at the tip, fluids dribbling down eir chin. The machine at eir throat presses em back into the wall with a choked gasp, but still ey strains forward, tongue outstretched to its fullest, eyebrows high.

Observing closely, you slide a lubed tentacle down eir belly, dip it between eir legs and rub, gently.

Houka bucks so violently it startles you into a half-step back. You quickly gather your composure, resuming your stance and digging your fingers back into your sleeves. Even with your mechanical arms stilled, your partner is wriggling, body arching towards contact. The machines pinning eir limbs appear intact, at least, with no sign of giving way to eir struggles.

Filtering through your gasmask is the sweet acrid smell of sweat, musky in the air; combined with the sharp metal and sour notes of your equipment, it's almost heady. You breathe deeply, trying to oxygenate your lungs, anchor yourself in your body. You eye Houka's right hand, still gripping its marble tight, and close your eyes momentarily. Assessment.

Yes.

You're fine.

A little frightened, perhaps.

But present.

You open your eyes, and are relieved to find Houka still panting but watching you, soft concern obvious in eir half-lidded gaze. You tip your head to the left, a small smile on your lips that you know shows in your eyes, and press the lower tentacle onward.

Ey moans and rocks forward, squeezing eir eyes shut as your sewing machine hisses at eir throat. Delicately, you slide along eir lower skin, twisting as you meet the wall to wind up to eir lower back instead. You have the oral arm caress eir right cheek, the uncommitted one wander along hips, and the lower slowly slip down between eir folds. 

Houka whimpers and looks down at you, eyes wet and pleading. You tease at eir tongue, probing both mouth and the entrance between eir legs, softly pulsing back and forth. Eir mouth yearns toward your evasive tentacle, catching it to lick for but a moment before it dances away again. You feel em getting looser, your arm gaining more room to undulate against contracting and relaxing muscle. Eir breaths are getting shorter.

You draw both teasing limbs away, to immediate complaint; then, your partner's breath hitches instead, cutting off eir whine, as ey sees you re-dipping the tentacles in the lube. Ey swallows, legs twitching wider; you trace your free arm down eir left thigh, wrapping round its length and holding em open.

Unhurried, your newly lubricated tentacles glide back through the air, rippling in generous S's. They brush over heart and navel before drifting back to where they were before, nuzzling and probing once more. Houka groans at their touch, shifting in place; your machine purrs at eir throat. Gradually, ey relaxes, limbs losing some of their tension as ey laps peacefully at your tip.

You hold your breath when eir eyes roll back and mouth goes wide, both tentacles slipping gently in. Ey pants, rhythmically, each breath a little more vocal than the last. With infinite slowness, you sustain a steady forward pressure, letting Houka's rocking do the work. You sense the muscles contracting and closing the space around your limb just as ey arches off the wall, hips out and head back with a blissful full-mouthed moan.

Houka is so beautiful.

Tenderly, you shift your arms back and forward again, the tiniest of motions. Your partner moves with you, against you, around you, pulling you deeper. Ey chokes on you, shuddering, and still pushes further, quivering as tears start to stream down eir face. Ey jerks eir waist and jolts back with a muffled cry, head tipped back against the wall, hips arced out far they can go.

You glance to Houka's right hand, white-knuckled from still clutching the marble. You don't stop.

Ey is gasping for every breath at this point, full out weeping, drenched in sweat and lube and snot and drool. Eir eyes are glazed over, unseeing, lids fluttering purely out of instinct. The combination of daze and motion is unbelievably captivating.

You can't stand it anymore. You rip off your gasmask and step into point-blank range to touch your partner, your lover, your gloved fingers cupping Houka's face as you lean up on tiptoe against em and kiss where jaw meets ear. Ey convulses against you, sobbing, and as you hear the marble clatter to the floor you tenderly withdraw your mechanical arms while wrapping your flesh-and-blood ones around em.

You make short work of reattaching machines to arms and withdrawing them from the wall, carefully lowering Houka to the floor and deactivating your uniform. You cradle eir head as ey trembles in your lap. Everything is sticky with fluids, especially the floor, but you don't trust yourself to carry em without your Regalia. You stroke eir sweat-soaked hair, murmuring quiet reassurances and watching as the tremors slowly subside.

The dozenth time you say "I've got you," Houka rolls eir head to look up at you, lips parted and eyes blinking unevenly. Your heart swells just looking at em; you feel your face split into a smile.

"Water?" you ask. "Blankets? Plushie, phone?"

Houka shakes eir head, blinks some more, and manages a faint smile, looking absolutely exhausted. You realize you're feeling rather shaky, yourself. You smooth eir cotton-candy hair back and, holding your own locks out of the way, lean down to press your lips to the cut on eir forehead.

When you straighten up, Houka is looking both peaceful and more alert. Ey starts to lick eir lips, grimaces, then wipes eir mouth with the back of eir hand, looks at it, and snorts.

"Shower?" you quip, voice as light as you feel. Your enbyfriend flashes you a grin, then blinks and turns to face the other way.

"Did you…fuck up the wall..?"

You swat your partner in the back of the head.

"Oww!" Ey rubs the afflicted spot and looks back over eir shoulder at you, face lit up with a mischievous smirk.

"Yes, well." You don't bother to try to keep the fondness from your voice. "It was for science."

**Author's Note:**

> Further details involved: Shiro and Houka are in a queerplatonic kinky relationship and are both aromantic/-spectrum and autistic; plus, Shiro's pretty much asexual and Houka's more grey-ace. Also Shiro is paper maché, aka alternates between stone and paper, giving versus receiving touch; both at once is over-stimulating and not that pleasant. ((These didn't go in the tags because...reasons? Nervous reasons.))
> 
> Huge kudos to @venomousOctopus and @gungnirburst, whose ShiHou fics (particularly "Sleazy"), headcanons and ideas were massively inspiring to me. And a million thanks to @mxfictiondaydreamer for being my springboard, motivator, dictionary, and friend.


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